This report presents the findings of a follow-up to the Head Start Impact Study. In an effort to examine longer term effects of both early and late Head Start participation on a variety of children's outcomes, this study compares select grade-school age measures from the original randomized and controlled groups of children through the end of third grade. Findings revealed that, while there were initial benefits from Head Start program participation, by the end of third grade very few impacts were found in either cohort in the areas of cognitive development, social-emotional development, health, or behavior.